MODULE 1- Studying the Nervous System Flashcards
1
Q
2 primary cell types of all nervous systems
A
-neurons
-glia
2
Q
**neurons
A
come in a wide variety of sizes, shapes, + the number + complexity of processes (dendrites + axons)
3
Q
dendrites
A
part of neuron that RECEIVES information from other neurons
4
Q
axons
A
part of neuron that SENDS/TRANSMITS information
5
Q
**synapse
A
the point of communication between 2 neurons
6
Q
neuronal axons are wrapped in ____
A
myelin
7
Q
**what creates myelin in the CNS
A
oligodendrocytes
8
Q
**what creates myelin in the PNS
A
Schwann cells
9
Q
what occurs at the soma of a neuron
A
protein synthesis
-proteins + organelles must be trafficked long distances to the end of the terminal
10
Q
**shape of neurons
A
highly polarized
-a long axon with a distant terminal from which synaptic vesicles release neurotransmitters
11
Q
axons can be up to how long
A
1 meter
12
Q
a taller person has what
A
longer axons compared to someone that is short
13
Q
what does a postsynaptic cell have
A
receptors for neurotransmitters
14
Q
**divergence
A
few presynaptic cells to many postsynaptic cells
15
Q
**convergence
A
many presynaptic cells to few postsynaptic cells
16
Q
glia
A
cells that hold nerve cells in place + help them work the way they should
17
Q
**glia in CNS
A
-astrocytes
-oligodendrocytes
-microglia
18
Q
**astrocytes
A
-help with blood-brain barrier
-buffer ions + neurotransmitters
-secrete chemicals for synaptogenesis
19
Q
synaptogenesis
A
formation of new synapses
-new + more connections between neurons
20
Q
**oligodendrocytes
A
myelinate neuronal axons
21
Q
**microglia
A
-perform immune function for CNS, considered “immune cells” of CNS
-macrophage activity
-secrete cytokines
22
Q
**glia in PNS
A
Schwann cells
23
Q
**Schwann cells
A
-myelinate neuronal axons
-participate in recovery of function resulting from neuronal damage
24
Q
3 ways to visualize neurons in the CNS + PNS
A
-golgi stain
-flourescent dye
-Nissl stain
-using different stains/dyes can trace how neurons connect to other neurons
-important for understanding how neural circuits are formed
25
neural circuits
neurons are interconnected in ensembles called neural circuits
-neurons don’t function in isolation but rather work together to form neural circuits
26
**afferent
towards CNS
-away from periphery/effectors
27
effectors
muscles, organs, etc.
28
**efferent
away from CNS
-toward periphery/effectors
29
**3 ways signals can be classified
-excitatory
-inhibitory
-modulatory
30
**interneurons
participate in local circuit function
31
describe axons of interneurons
short axons
32
myotatic reflex is also called
knee-jerk reflex
33
myotatic (knee-jerk) reflex is controlled by what
simple neural circuit
34
reason for myotatic (knee-jerk) reflex
to maintain an upright posture in the face of unexpected changes (such as tripping)
35
in myotatic (knee-jerk) reflex, flexors are ____ + extensors are ____, causing ____
-flexors are INHIBITED
-extensors are EXCITED
-causing leg extension
36
describe how myotatic (knee-jerk) reflex occurs
-stimulation of peripheral sensors (a muscle stretch receptor) initiates receptor potentials that trigger APs that travel centrally along the afferent axons of the sensory neurons
-this information stimulates spinal motor neurons by means of synaptic contacts
-the APs triggered by the synaptic potential in motor neurons travel peripherally in efferent neurons, giving rise to muscle contraction + a behavioral response
37
recording from various places in the reflex loop of the myotatic reflex while responding
-sensory neuron
-interneuron
-motor neuron (extensor)
-motor neuron (flexor)
38
**optogenetics
a technique for controlling the communication between neurons
-genes for light-sensitive proteins (ex: opsins) are introduced into certain neurons to monitor + control their activity in response to light signals -> chemical signals
39
circuits that process related information constitute a ____
neural system
40
neural systems
organization of individual neural circuits according to the type of information they carry into broader networks + larger volumes so that more complex behaviors can be generated
41
neural systems have ____
unity of function
42
do neural circuits exist in isolation
no
-found in neural systems
43
how are neural systems organized
organized into representations of information that are processed in parallel pathways, culminating in topographic maps
44
computational map
additional information processing based on time or order of input
45
sensory motor system
neural system that controls how we process sensory information + controls movements
46
structural analysis of neural systems
-lesion studies reveal the direction of information flow
-labeling specific proteins
47
neural systems- function
determine what neurons do from moment to moment in a neural system
48
**receptive field
the region in sensory space to which a neuron will respond
49
**single unit responding
using single unit responding, it is possible to find the relationship between peripheral stimuli + neuronal responses
50
example defining relationships between peripheral stimuli + neuronal responses using single-unit recording
-this example is from a cortical pyramidal neuron in the somatosensory cortex of a rhesus monkey, showing the firing pattern in response to a specific peripheral stimulus (pressure applied to a discrete point on the skin surface) in the anesthetized animal
-typical experiment setup, in which a recording electrode is inserted into the somatosensory cortex in the postcentral gyrus
-defining neuronal receptive fields based on the location of the peripheral stimulus in the sensory space (in this case, a particular region of the arm) that elicits the maximal response from the CNS neuron whose AP activity is being recorded, referred to as the receptive field center
-the flanking region (called the surround) is the region of the skin surface that when stimulated will actually diminish the response of the same neuron
51
**CNS
brain + spinal cord
52
**PNS
extension of the CNS beyond the brain + spinal cord into the periphery
-consists of everything else outside of CNS, including sensory nerves, motor nerves, spinal + cranial nerves, autonomic ganglia, enteric nervous system, etc.
53
afferent
PNS sensory info sent to CNS
54
efferent
CNS motor (visceral + somatic) commands are sent to PNS
55
motor components consist of what 2 systems
-visceral motor sysem
-somatic motor system
56
visceral motor system
-sympathetic, parasympathetic, + enteric divisions
-autonomic ganglia + nerves
57
somatic motor system
motor nerves
58
effectors
-smooth muscles, cardiac muscles, + gland
-skeletal (striated) muscles
59
what does the genome control
brain organization + function
60
how are proteins made
genes (DNA) makes RNA ->
RNA makes protein
61
**genomics
analysis of the complete DNA sequence of a species or individual
62
depending on the gene, a single mutation in the DNA can...
have devastating consequences on brain development
63
what can be analyzed in the human brain
neural circuits + systems
64
3 things that imaging in the living brain is used for
-discerning various anatomical structures
-diagnoses of medical problems, such as tumor or stroke
-to characterize the activity of the brain as it performs complex tasks, such as problem-solving, recall, speaking, singing, + so much more
65
minimally invasive analysis of human brain function
-EEG
-TMS
66
**electroencephalogram (EEG)
can map the brain according to event-related potentials (ERPs)
67
**transcranial magnetic stimulation (TMS)
used to correlate broad areas of the brain with ongoing behavior
-used for neurologic + psychiatric conditions
-uses electromagnetic coil
68
radiographic methods for brain imaging
-x-rays
-CT
-PET
69
**computerized tomography (CT)
x-rays narrowed into a tube sweeps across the brain, providing detailed anatomical structure
70
**positron emission tomography (PET)
patient is injected with a radio-labeled molecule, such as dopamine, which is then taken up by certain neurons (ex: those of the basal ganglia)
71
CT or PET is more functional
PET
72
downside to PET
more invasive, since radioactive isotope is injected
73
magnetic resonant imaging
-MRI
-DTI
74
**MRI
ALL YOU NEED TO KNOW- MRI causes hydrogen atoms to act like magnets
-when placed in a magnetic field, a patient (+ his protons (H+)) will line up with the magnetic field + spin at a frequency that depends on the field strength; a brief radiofrequency pulse applied tuned to the atoms’ spinning frequency emit ENERGY as they realign themselves with the field
75
**DTI (diffusion-tensor imaging)
detects white matter tracts because water molecules can diffuse in limited directions along the length of the axon
76
what is DTI useful for
diagnoses
77
functional brain imaging
-fMRI (+ BOLD)
-MEG
-MSI
78
**fMRI
based on METABOLIC ACTIVITY (OXYGEN-DEPENDENT) of the brain
-ideal to determine which areas of the brain are metabolically active (functioning) when performing a certain task, such as reading or speaking
79
**blood oxygen level-dependent (BOLD)
when neurons are active, they require more oxygen so they can function, which is varied by the blood
-with BOLD fMRI we are basically tracking blood flow; measures brain activity by detecting changes in blood oxygenation levels
80
**magnetoencephalograhy (MEG)
records the magnetic consequences of the brain’s electrical activity
81
fMRI or MEG provides greater temporal resolution
MEG
82
magnetic source imaging (MSI)
combines structural MRI with MEG
83
analyzing complex behavior
-complex behaviors such as perception, language, emotions, consciousness, memory
-imaging techniques, such as fMRI can be combined with the principles of cognitive neuroscience, which focuses on the underlying structural + functional representations manifesting as behaviors
